The present disclosure relates to a semiconductor device, and more particularly, to a semiconductor device configured to perform a calibration operation without having a ZQ pin.
A swing width of signals is decreasing so as to minimize a transmission time of signals interfacing between semiconductor devices. As the swing width of the signals decreases, an effect of external noise on the semiconductor devices increases, and signal reflection that may be caused by impedance mismatching in an interface may become a serious problem. If impedance mismatch occurs, it may be difficult to transmit data at a high speed, and data output from an output terminal of a semiconductor device may be distorted. Accordingly, since the semiconductor device for receiving the data may receive a distorted signal, problems such as a setup/hold failure, misjudgment, or the like may frequently occur.
In order to address these issues, memory devices include a ZQ pin, and control impedance matching by receiving a ZQ calibration command (for example, ZQ calibration short (ZQCS) or ZQ calibration long (ZQCL)) from outside and performing ZQ calibration. From among memory devices, a memory device that does not have a ZQ pin may also need to perform a calibration operation for accurate impedance matching.